Validate Object Class — check

A internal input checker function to validate whether an object belongs to the expected class, providing clear and informative {cli}-style error messages.

Usage

check_class(
  x,
  class,
  inlist = FALSE,
  class_fn = NULL,
  arg = rlang::caller_arg(x),
  call = rlang::caller_env(),
  return_msg = FALSE
)

Arguments

x: the target object to validate. If a list, each element will be checked against the expected class
class: character string, the name of the expected class of x.
inlist: logical, whether to take x as a list containing objects of the expected class
class_fn: character string, indicating the function to create objects of the expected class, in the form of "packagename::functionname".
arg: An argument name as a string. This argument will be mentioned in error messages as the input that is at the origin of a problem.
call: The execution environment of a currently running function, e.g. caller_env(). The function will be mentioned in error messages as the source of the error. See the call argument of abort() for more information.

Details

This is an input checker function, i.e. it is intended for internal use within other functions to check their inputs - it acts on behalf of other functions as their input validator.

If x is a list, the function checks each element individually, throwing an error if any element does not belong to the expected class.

class_fn is optional, and is used to generate a link in the error message to the function's manual page, if available.